No. 31.— 1885.] 



PLUMBAGO. 



231 



as of permanent value, will be found as a note to this 

 paper.* 



The figures are said, truly, to prove the often-repeated 

 claim of the dealers in Canadian and American graphite 

 that it is equal to the best Ceylon. The claim, pre-supposing 

 that the samples were fairly chosen, must be fully conceded, 

 for while the highest percentage of carbon in the Ceylon 

 specimens analyzed is 99*792 per cent., the best Canadian 

 is actually up to 99*815. The Ceylon mineral seems to 

 have had a few fractions more of volatile matter. Both are 

 almost absolutely pure, and did the Canadian and United 

 States mineral occur in such a form in the enclosing rocks 

 that it could be cheaply mined and prepared, there would 

 of course be an end of the export of Ceylon plumbago to 

 America. But if, in America, plumbago, however pure, is 

 only distributed in the proportion of 8 to 15 per cent, mineral 

 to 92 to 85 rock, those connected with the Ceylon enterprise 

 need not, it would seem, concern themselves greatly with the 

 competition in America of indigenous ore with that from 

 our island. In view of analyses which give results so near 

 100 per cent, of carbon, we may well be amazed at the fact 

 that the specific article on "Plumbago" in the new edition of 

 the Encyclopedia Britannica should characterize graphite 



* Analyses of Canadian and Ceylon Graphites. 



Locality. 



Specific 

 Gravity, 



Volatile 

 Matter. 



Carbon, 



Ash. 



Canada, Buckingham ; vein graphite ; 





per cent. 



per cent. 



per cent. 



variety, foliated 



2.2689 



0.178 



99.675 



0.147 



Canada, Buckingham ; vein graphite ; 









variety, columnar 



2.2679 



0.594 



97.626 



1.780 



Canada, Grenville ; vein graphite ; 









variety, foliated 



2.27U 



0.109 



99.815 



0.070 



Canada, Grenville; vein graphite; 











variety, columnar 



2.2659 



0.108 



99.757 



0.135 



Ceylon; vein graphite; variety, co- 











lumnar ... 



2.2671 



0.158 



99.792 



0.050 



Ceylon ; vein graphite ; variety, foli- 











ated 



2.2664 



0.108 



99.679 



0.213 



Ceylon; vein graphite; variety, co- 











lumnar ... 



2,2546 



0.900 



98.817 



0.283 



Ceylon ; vein graphite ; variety, foli- 











ated 



2.2484 



1 0.301 



99.2S4 



0.415 



